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US2578075A - Brownprint fixing composition containing alkali thiosulfate, alkali oxalate, and a surface active wetting agent - Google Patents

Brownprint fixing composition containing alkali thiosulfate, alkali oxalate, and a surface active wetting agent Download PDF

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US2578075A
US2578075A US100093A US10009349A US2578075A US 2578075 A US2578075 A US 2578075A US 100093 A US100093 A US 100093A US 10009349 A US10009349 A US 10009349A US 2578075 A US2578075 A US 2578075A
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alkali
oxalate
brownprint
wetting agent
fixing
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US100093A
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John F Kienast
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Keuffel and Esser Co
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Keuffel and Esser Co
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
    • G03C1/00—Photosensitive materials
    • G03C1/64—Compositions containing iron compounds as photosensitive substances

Definitions

  • This invention relates to a new brownprint fixing composition and process. It is a continuation in part of copending application, Serial No. 597,719, filed June 5, 1945, now abandoned.
  • Brownprints also known in the trade as sepia and Van Dyke prints, are produced by coating on a base material, usually paper, a composition containing a light-sensitive ferric salt of an organic acid, such as the citrate or oxalate, a soluble silver salt, such as silver nitrate, and a salt that will act as a solvent for the ferrous salts that are eventually formed.
  • This latter salt usually is an alkali salt of a polycarboxylic acid, such as the sodium, potassium, or ammonium salts of oxalic acid.
  • the most active of these are the oxalates but they have a limited compatability with the silver nitrate and their use in a sensitizing coating composition is therefore restricted to relatively small amounts when in the same solution.
  • the sensitized sheet When used, the sensitized sheet is exposed to actinic light under a tracing or the like for the purpose of producing a negative print.
  • the action of the light on the exposed areas reduces the trivalent ferric iron to the bivalent ferrous form, which when dissolved in situ by the alkali salt of an organic acid, reduces the silver nitrate to give a brownish image of silver.
  • hypo sodium thiosulfate
  • the present invention provides an improved fixing composition and solution thereof which will rapidly remove both iron salts, whether in ferric or ferrous condition, and silver salts, thus making for a permanent print with clean whites and dense images.
  • the present invention also provides an im.- proved fixing process in which the brownprint is subjected to the new fixing solution.
  • the improved composition and process are adapted for use according to the common tub washing and fixing procedure but particular advantages are derived when they are used on fast continuous printing machines.
  • an alkali oxalate is used together with the customary hypo (sodium thiosulfate), or other alkali thiosulfate, the alkali oxalate acting in a twofold capacity. It is a powerful solvent for undissolved ferric and ferrous iron salts that remain on they sheet after the first water wash and it also permits the use of an increased concentration of hypo by retarding the bleaching eifect that strong solutions of the latter would ordinarily have on the image.
  • the fixing composition and process are materially and advantageously improved by also including in the composition a suitable surface active wetting agent, for example, modified sodium lauryl sulfate.
  • a suitable surface active wetting agent for example, modified sodium lauryl sulfate.
  • the addition of such a wetting agent was found to speed up the solvent and fixing action of the solution containing hypo and oxalate to such an extent that the amounts of these. agents could be very materially reduced, e. g., 2 ounces of potassium oxalate plus 2 ounces of hypo, plus 10 grams of the wetting agent giving similar results to those obtained with 4 ounces of potassium oxalate and 4 ounces of hypo per gallon of water when the wetting agent was not included.
  • composition can be prepared in the form of a solution, it is advantageously prepared in the form of a dry composition, which can be packaged and shipped and stored and used by adding it to water to form the fixing solution.
  • hypo is advantageously used in the form of the anhydrous salt.
  • ordinary hypo containing 5 mols. of water of crystallization is not well adapted for admixture, e. g., with potassium oxalate because of the tendency ofthe water to cause the composition to.
  • ammonium oxalate is particularly advantageous for use in the new composition. Although ammonium oxalate is much less soluble than the potassium salt, it nevertheless has a sufficient solubility for use according to the present invention.
  • the dry composition can readily be made and packaged, shipped and stored.
  • the composition is dissolved in water in the proportions of e. g., 4 ounces per gallon. Due to the hydrolysis of the sodium and ammonium salts, the water solution will be non-acid and in fact somewhat alkaline in nature.
  • the brownprint sheet coated with a ferric salt and a soluble silver salt is exposed to light through an original or master to reduce the ferric salt to a ferrous salt in the light struck areas.
  • the sheet is then washed with water to develop the image by allowing the ferrous ions to reduce the soluble silver salt to metallic sil-. ver and by dissolving the major portion of the excess salts from the sheet.
  • the sheet is subjected to the new fixing solution which fixes the print by removing any remaining silver salts and iron salts from the unexposed areas.
  • the sheet is then given a final water wash to remove the fixing salt and the iron and silver salts dissolved thereby.
  • the new composition is advantageously prepared in the form of a dry composition containing anhydrous hypo, the alkali oxalate and wetting agent, mixed together in proper proportions and packaged in packages of suitable size, such that, e. g., 1 pound may be dissolved in 4 gallons of Water or 4 ounces dissolved in 1 gallon of water to give the fixing solution.
  • the new fixing solutions can, however, be made by adding each of the individual agents in suitable proportions to water or by combining two of the agents together, e. g., the ammonium oxalate and Wetting agent in proper proportions and adding these and the hypo to form the fixing solution.
  • the wetting agent used should be one which is compatible with the hypo and oxalate and while different wetting agents can be used the alkali metal salts of sulfated higher alcohols appear to be particularly advantageous.
  • dry wetting agents such as hydrocarbon sodium sulfonate, sodium alkyl sulfates, principally sodium lauryl sulfate, iso propyl naphthalene sodium sulfonate, sodium salt of sulfated monoglyceride, and sodium salt of the oleic acid amide of sulfonated ethyl alcohol, may be used.
  • many other wetting agents can be used where the original container permits a. fluid condition for the developer or where the ingredients are individually added to the solution which is to be the fixing solution.
  • a typical fluid wetting agent is a solution of sodium sulfate derivative of 3,9-diethyl tridecanol-G.
  • the present invention enables standard apparatus and procedure to be followed, using the new fixing solution in place of hypo; and that the process is particularly advantageous for use in high speed machines and as a high speed fixing process.
  • An anhydrous composition for forming a brownprint fixing solution by the addition of water thereto consisting essentially of from 20 to 60% of anhydrous alkali thiosulfate, from to 30% of alkali oxalate and from 0 to 10% of a dry surfaceactive wetting agent compatible therewith.
  • a composition for forming a brownprint fixing solution by the addition of water thereto consisting essentially of from 20 to 60% of sodium thiosulfate, from 80 to 30% of alkali oxalate and from 0 to 10% of a dry surface active wetting agent compatible therewith.
  • An anhydrous composition for forming a brownprint fixing solution by the addition of water thereto consisting essentially of approximately 32% anhydrous sodium thiosulfate, 60% ammonium oxalate and 8% modified sodium lauryl sulfate surface active wetting agent.
  • An improved brownprint fixing solution consisting essentially of from 20 to 60% of alkali thiosulfate, from 80 to 30% of alkali oxalate and from to of a surface active wetting agent compatible therewith dissolved in water in the proportion of approximately 4 ounces of the specified three ingredients in their indicated proportions to one gallon of water.
  • a composition for forming a brownprint fixing solution by the addition of water thereto consisting essentially of from 20 to 60% of anhydrous alkali thiosulfate, from 80 to 30% of alkali oxalate and from 0 to 10% of a modified sodium lauryl sulfate surface active wetting agent.
  • a composition for forming a brownprint fixing solution by the addition of water thereto consisting essentially of from 20 to 60% of anhydrous alkali thiosulfate, from 30 to 30% of alkali oxalate and from 0 to 10% of a surface active wetting agent selected from the group consisting of alkali salts of sulfated higher alcohols, hydrocarbon alkali sulfonates, alkali salts of sulfated mono-glycerides and alkali salts of the oleic acid amide of sulfonated ethyl alcohol.
  • An improved brownprint fixing solution consisting essentially of from 20 to 60% of alkali thiosulfate, from 80 to 30% of alkali oxalate and from 0 to 10% of a surface active wetting agent selected irom the group consisting of alkali salts of sulfated higher alcohols, hydrocarbon alkali sulfonates, alkali salts of sulfated mono-glycerides and alkali salts of the oleic acid amide of sulfonated ethyl alcohol dissolved in water in the proportion of approximately 4 ounces of the specified three ingredients in their indicated proportions to one gallon of water.
  • a surface active wetting agent selected irom the group consisting of alkali salts of sulfated higher alcohols, hydrocarbon alkali sulfonates, alkali salts of sulfated mono-glycerides and alkali salts of the oleic acid amide of sulfonated ethyl

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Silver Salt Photography Or Processing Solution Therefor (AREA)

Description

Patented Dec. 11, 1951 BROWNPRINT FIXING COMPOSITION CQN TAINING ALKALI THIOSULFATE, ALKALI OXALATE, AND A SURFACE ACTIVE WET- TING AGENT John F. Kienast, River Edge, N. .L, assignor to, Keuifel & Esser Company, Hoboken, N. J;,, a. corporation of New Jersey No Drawing. Application June 18, 1943, Serial No. 100,093
'7 Claims.
This invention relates to a new brownprint fixing composition and process. It is a continuation in part of copending application, Serial No. 597,719, filed June 5, 1945, now abandoned.
Brownprints, also known in the trade as sepia and Van Dyke prints, are produced by coating on a base material, usually paper, a composition containing a light-sensitive ferric salt of an organic acid, such as the citrate or oxalate, a soluble silver salt, such as silver nitrate, and a salt that will act as a solvent for the ferrous salts that are eventually formed. This latter salt usually is an alkali salt of a polycarboxylic acid, such as the sodium, potassium, or ammonium salts of oxalic acid. The most active of these are the oxalates but they have a limited compatability with the silver nitrate and their use in a sensitizing coating composition is therefore restricted to relatively small amounts when in the same solution.
When used, the sensitized sheet is exposed to actinic light under a tracing or the like for the purpose of producing a negative print. The action of the light on the exposed areas reduces the trivalent ferric iron to the bivalent ferrous form, which when dissolved in situ by the alkali salt of an organic acid, reduces the silver nitrate to give a brownish image of silver. After exposure it is the custom to wash the print in water. This wash puts the alkali salt of an organic acid into solution so that the reaction mentioned may take place. Thereafter the sheet is fixed with a solution of hypo (sodium thiosulfate) to dissolve the unexposed silver salts, and then given a final wash in water.
Under conditions of unhurried washing and fixing schedules, good prints with stable white areas are readily obtainable from coatings of this type. However, modern continuous printing machines have such high powered lights that only very short exposures are required with correspondingly curtailed washing and fixing operations. Brownprints made in this manner were often found to have lines and other unexposed areas that were discolored or that became discolored after a short time. I have found this discoloration to be due primarily to undissolved iron salts although silver salts were present in minute amounts.
The present invention provides an improved fixing composition and solution thereof which will rapidly remove both iron salts, whether in ferric or ferrous condition, and silver salts, thus making for a permanent print with clean whites and dense images.
The present invention also provides an im.- proved fixing process in which the brownprint is subjected to the new fixing solution.
The improved composition and process are adapted for use according to the common tub washing and fixing procedure but particular advantages are derived when they are used on fast continuous printing machines.
In the new fixing composition an alkali oxalate is used together with the customary hypo (sodium thiosulfate), or other alkali thiosulfate, the alkali oxalate acting in a twofold capacity. It is a powerful solvent for undissolved ferric and ferrous iron salts that remain on they sheet after the first water wash and it also permits the use of an increased concentration of hypo by retarding the bleaching eifect that strong solutions of the latter would ordinarily have on the image. For example, by dissolving four ounces of potassium oxalate and four ounces of hypo (sodium thiosulfate) in one gallon of water, a solution was obtained which produced, when used in place of the usual hypo fixing solution, a print having better and more permanent whites with improved density and image color.
The fixing composition and process are materially and advantageously improved by also including in the composition a suitable surface active wetting agent, for example, modified sodium lauryl sulfate. The addition of such a wetting agent was found to speed up the solvent and fixing action of the solution containing hypo and oxalate to such an extent that the amounts of these. agents could be very materially reduced, e. g., 2 ounces of potassium oxalate plus 2 ounces of hypo, plus 10 grams of the wetting agent giving similar results to those obtained with 4 ounces of potassium oxalate and 4 ounces of hypo per gallon of water when the wetting agent was not included.
While the composition can be prepared in the form of a solution, it is advantageously prepared in the form of a dry composition, which can be packaged and shipped and stored and used by adding it to water to form the fixing solution. In such a composition the hypo is advantageously used in the form of the anhydrous salt. The use of ordinary hypo containing 5 mols. of water of crystallization is not well adapted for admixture, e. g., with potassium oxalate because of the tendency ofthe water to cause the composition to.
form a sludge. Byusing the anhydrous hypo a satisfactory dry composition. can readily be prepared.
While sodium and. potassium oxalates may be used, ammonium oxalate is particularly advantageous for use in the new composition. Although ammonium oxalate is much less soluble than the potassium salt, it nevertheless has a sufficient solubility for use according to the present invention.
The following approximate proportions have been found to be particularly advantageous especially for one commercial type of brownprint paper:
Per cent Anhydrous sodium thiosulfate 32 Ammonium oxalate 60 Wetting agent (e. g. modified sodium lauryl sulfate) 8 However, the proportions may be varied within the following limits to still produce an effective fixing composition.
Per cent Anhydrous alkali thiosulfate 20 to 60 Alkali oxalate 80 to 30 Wetting agent Oto The proportions which are chosen within the above ranges may to some extent be dependent on the particular brownprint paper with which the fixingsolution is intended to be used. This is true because commercial brownprint papers do not all have the same proportion of light reducible ferric salt to soluble silver salt and consequently, a composition having a different proportion of ammonium oxalate to sodium thiosulfate than that given in the specific example may be somewhat more effective for certain brownprint papers. It would be a relatively simple matter to determine the best proportions for any particular brownprint material.
The dry composition can readily be made and packaged, shipped and stored. In order to make the new fixing solution the composition is dissolved in water in the proportions of e. g., 4 ounces per gallon. Due to the hydrolysis of the sodium and ammonium salts, the water solution will be non-acid and in fact somewhat alkaline in nature.
The procedure for forming brownprints making use of the new fixing solution may be described as follows:
The brownprint sheet coated with a ferric salt and a soluble silver salt is exposed to light through an original or master to reduce the ferric salt to a ferrous salt in the light struck areas. The sheet is then washed with water to develop the image by allowing the ferrous ions to reduce the soluble silver salt to metallic sil-. ver and by dissolving the major portion of the excess salts from the sheet. Then the sheet is subjected to the new fixing solution which fixes the print by removing any remaining silver salts and iron salts from the unexposed areas. The sheet is then given a final water wash to remove the fixing salt and the iron and silver salts dissolved thereby.
When my solution is used in place of the customary straight hypo fixing solution a much more rapid and thorough washing out of unexposed salts is accomplished with the result that cleaner whites are obtained in a shorter time. If the old standard washing and fixing scheduled of 2 to 3 minutes first water washing, 1 to 2 minutes in fixing solution and /2 to 1 minute of final water wash is followed, the new fixing solution will effect removal of all unexposed iron and silver salts so that the masked portions of the print will have the same permanent whiteness as the paper stock. A
straight hypo fixing solution does not accomplish this result particularly on the more retentive, transparentized or "treated papers; hypo being a solvent for the unexposed silver salts only, does not remove the iron salts.
It is an advantage of the present invention that it facilitates the more rapid removal of unexposed iron and silver salts from the brownprint process papers. While giving noticeably better results even in the old fashioned tub washing and fixing procedure, the new composition is particularly designed and advantageously used, in high speed printing machines that operate on a relatively short washing and fixing schedule. Another advantage presented by the present invention is the tendency to overcome any bleaching diificulties that arise when a printer attempts to compensate for the short fixing time by unduly increasing the concentration of his fixing salts.
The new composition is advantageously prepared in the form of a dry composition containing anhydrous hypo, the alkali oxalate and wetting agent, mixed together in proper proportions and packaged in packages of suitable size, such that, e. g., 1 pound may be dissolved in 4 gallons of Water or 4 ounces dissolved in 1 gallon of water to give the fixing solution.
The new fixing solutions can, however, be made by adding each of the individual agents in suitable proportions to water or by combining two of the agents together, e. g., the ammonium oxalate and Wetting agent in proper proportions and adding these and the hypo to form the fixing solution.
The wetting agent used should be one which is compatible with the hypo and oxalate and while different wetting agents can be used the alkali metal salts of sulfated higher alcohols appear to be particularly advantageous.
Thus other dry wetting agents such as hydrocarbon sodium sulfonate, sodium alkyl sulfates, principally sodium lauryl sulfate, iso propyl naphthalene sodium sulfonate, sodium salt of sulfated monoglyceride, and sodium salt of the oleic acid amide of sulfonated ethyl alcohol, may be used. In addition to these, many other wetting agents can be used where the original container permits a. fluid condition for the developer or where the ingredients are individually added to the solution which is to be the fixing solution. A typical fluid wetting agent is a solution of sodium sulfate derivative of 3,9-diethyl tridecanol-G.
From the standpoint of the fixing process it will be seen that the present invention enables standard apparatus and procedure to be followed, using the new fixing solution in place of hypo; and that the process is particularly advantageous for use in high speed machines and as a high speed fixing process.
What is claimed is:
1. An anhydrous composition for forming a brownprint fixing solution by the addition of water thereto consisting essentially of from 20 to 60% of anhydrous alkali thiosulfate, from to 30% of alkali oxalate and from 0 to 10% of a dry surfaceactive wetting agent compatible therewith.
2. A composition for forming a brownprint fixing solution by the addition of water thereto consisting essentially of from 20 to 60% of sodium thiosulfate, from 80 to 30% of alkali oxalate and from 0 to 10% of a dry surface active wetting agent compatible therewith.
3. An anhydrous composition for forming a brownprint fixing solution by the addition of water thereto consisting essentially of approximately 32% anhydrous sodium thiosulfate, 60% ammonium oxalate and 8% modified sodium lauryl sulfate surface active wetting agent.
4. An improved brownprint fixing solution consisting essentially of from 20 to 60% of alkali thiosulfate, from 80 to 30% of alkali oxalate and from to of a surface active wetting agent compatible therewith dissolved in water in the proportion of approximately 4 ounces of the specified three ingredients in their indicated proportions to one gallon of water.
5. A composition for forming a brownprint fixing solution by the addition of water thereto consisting essentially of from 20 to 60% of anhydrous alkali thiosulfate, from 80 to 30% of alkali oxalate and from 0 to 10% of a modified sodium lauryl sulfate surface active wetting agent.
6. A composition for forming a brownprint fixing solution by the addition of water thereto consisting essentially of from 20 to 60% of anhydrous alkali thiosulfate, from 30 to 30% of alkali oxalate and from 0 to 10% of a surface active wetting agent selected from the group consisting of alkali salts of sulfated higher alcohols, hydrocarbon alkali sulfonates, alkali salts of sulfated mono-glycerides and alkali salts of the oleic acid amide of sulfonated ethyl alcohol.
7. An improved brownprint fixing solution consisting essentially of from 20 to 60% of alkali thiosulfate, from 80 to 30% of alkali oxalate and from 0 to 10% of a surface active wetting agent selected irom the group consisting of alkali salts of sulfated higher alcohols, hydrocarbon alkali sulfonates, alkali salts of sulfated mono-glycerides and alkali salts of the oleic acid amide of sulfonated ethyl alcohol dissolved in water in the proportion of approximately 4 ounces of the specified three ingredients in their indicated proportions to one gallon of water.
JOHN F. KIENAST.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS OTHER REFERENCES Henney and Dudley: Handbook of Photography, McGraw-Hill, New York, 1939; page 386 cited.
Clerc: Photography: Theory and Practice," second edition, 1937; pages 406 and 408 cited.
Eder: Ausfuholiches Handbuch der Photographic, Band IV, 4 Teil, page 24 cited.

Claims (1)

1. AN ANHYDROUS COMPOSITION FOR FORMING A BROWNPRINT FIXING SOLUTION BY THE ADDITION OF WATER THERETO CONSISTING ESSENTIALLY OF FROM 20 TO 60% OF ANHYDROUS ALKALI THIOSULFATE, FROM 80 TO 30% OF ALKALI OXALATE AND FROM 0 TO 10% OF A DRY SURFACE ACTIVE WETTING AGENT COMPATIBLE THEREWITH.
US100093A 1949-06-18 1949-06-18 Brownprint fixing composition containing alkali thiosulfate, alkali oxalate, and a surface active wetting agent Expired - Lifetime US2578075A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2756151A (en) * 1952-08-01 1956-07-24 Eastman Kodak Co Reduction of dye stain in processed photographic papers containing dyes
US2860977A (en) * 1953-08-26 1958-11-18 Eastman Kodak Co Photographic foam processing
US3854947A (en) * 1973-05-16 1974-12-17 E Ritchey Process and solution for fixing an image on silver halide prints
US5328814A (en) * 1992-01-31 1994-07-12 Fuji Hunt Photographic Chemicals, Inc. Method of making flowable alkaline thiosulfate/alkaline sulfite and the product thereof

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US585452A (en) * 1897-06-29 Wilhelm schroter
US1411687A (en) * 1921-04-13 1922-04-04 Eastman Kodak Co Photographic bath
US1521840A (en) * 1921-05-06 1925-01-06 Eastman Kodak Co Acid-fixing bath
US1899674A (en) * 1932-04-28 1933-02-28 Western Union Telegraph Co Process for the production of ferric oxalate
US2000353A (en) * 1930-01-14 1935-05-07 Agfa Ansco Corp Process of treating photographic layers in a bath containing a wetting agent and new preparations intended for acting on photographic layers
US2101834A (en) * 1936-01-29 1937-12-14 Eastman Kodak Co Compositions of matter for photographic processing baths

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US585452A (en) * 1897-06-29 Wilhelm schroter
US1411687A (en) * 1921-04-13 1922-04-04 Eastman Kodak Co Photographic bath
US1521840A (en) * 1921-05-06 1925-01-06 Eastman Kodak Co Acid-fixing bath
US2000353A (en) * 1930-01-14 1935-05-07 Agfa Ansco Corp Process of treating photographic layers in a bath containing a wetting agent and new preparations intended for acting on photographic layers
US1899674A (en) * 1932-04-28 1933-02-28 Western Union Telegraph Co Process for the production of ferric oxalate
US2101834A (en) * 1936-01-29 1937-12-14 Eastman Kodak Co Compositions of matter for photographic processing baths

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2756151A (en) * 1952-08-01 1956-07-24 Eastman Kodak Co Reduction of dye stain in processed photographic papers containing dyes
US2860977A (en) * 1953-08-26 1958-11-18 Eastman Kodak Co Photographic foam processing
US3854947A (en) * 1973-05-16 1974-12-17 E Ritchey Process and solution for fixing an image on silver halide prints
US5328814A (en) * 1992-01-31 1994-07-12 Fuji Hunt Photographic Chemicals, Inc. Method of making flowable alkaline thiosulfate/alkaline sulfite and the product thereof
USRE35795E (en) * 1992-01-31 1998-05-12 Fuji Hunt Photographic Chemicals, Inc. Method of making flowable alkaline thiosulfate/alkaline sulfite and the product thereof

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